The majority of buildings, including most single-family and multi-family residences and a large percentage of commercial, institutional, and public buildings constructed in the United States, are framed with wood. Light wood-frame construction adapts readily to the most intricate spaces and architectural forms. The typical platform framing technique, which is also the most common light framing construction technique, requires selecting, measuring, cutting, drilling, and assembling many components. Such components typically include a sill sealer, a sill plate, anchors, a rim board (or joist), joists, subfloor panels, and an optional termite shield.
Typically, the sill plates and rim boards serve as the starting point for the remainder of the construction process, as shown in FIG. 1. The sill plate L is secured to a foundation F and provides a nailing base for the other adjoining members. The rim board R is placed on-edge and on top of the sill plate L around the outer perimeter of the floor system and transfers stacking gravity loads, such as aligned bearing walls, into the foundation. The rim board R also ties the joists J together, thereby improving lateral load resistance of the structure. Subflooring panels P are secured to the joists and J and the rim board R. Once the subflooring panels P are installed, the exterior walls of the building are constructed using a bottom plate B, one or more studs S, and top plates (not shown).
Generally, the material used for the rim board is insufficiently flexible and, thus, requires fine tune adjustment to ensure planarity as it is being fastened to the joists, rim board, and adjacent rim boards. The time it takes to make the adjustments is wasteful. Additionally, the quality of materials for the sill plate supplied to the jobsite is often of questionable performance. Thus, the framers typically need to sort through the supply to locate sufficient quality boards, which takes time and is wasteful both in material and labor costs.
Proper installation of the sill plates contributes to the finished product quality. If the sill plates are installed correctly (when the sill plates and rim boards are straight and square), the remainder of the construction process will be faster as fewer adjustments are needed. Many times, however, the foundation is not constructed to the specifications required. A homeowner will see the results of a foundation that is more than ⅜ inch out of level or square since these defects translate into visible quality issues of finished materials. For example, tile grout lines will be noticeably out of square with the top of the wall, or hardwood floor boards will appear wedge shaped where the floor meets the wall. Moreover, minor errors at the foundation framing can be exaggerated at the top plate, and the roof trusses may not fit without manual racking. Thus, correcting out of square or out of level foundations typically must take place when installing the sill plate and rim board assembly.
In addition to the construction problems caused by out of level and square foundations, variations in the foundation create air-leakage points where the sill plate does not conform to the foundation. Current sill sealing practices are insufficient to provide an air tight seal between the concrete foundation and the lower surface of the sill plate. There are additional leak paths between the sill plate and the rim board and the top of the rim board and the bottom surface of the sub-floor that are unaddressed in most construction practices. These leak paths allow air infiltration into the wall cavity where it greatly reduces the insulation effectiveness. These air-leakage points can lead to significant energy losses. Additional significant energy losses occur through conduction of heat energy through large structural member areas such as the rim board.